90% of JQuery

jquery-light.js

/**
 * 90% of JQuery
 * @param {String} cssSelectorString: any valid css selector syntax
 * @returns for ID selectors: Element
 * @returns for others: Element[] (NodeList)
 */
export const $ = cssSelectorString =>
  /^#/.test(cssSelectorString)
    ? document.querySelector(cssSelectorString)
    : document.querySelectorAll(cssSelectorString);

/**
 * 95% of JQuery
 * - accepts multiple selectors space-separated
 * @param {String} cssSelectorString
 */
export const $95 = cssSelectorString => {
  return / +/.test(cssSelectorString)
    ? cssSelectorString.split(" ").reduce((flatResults, selector) => {
        const result = $95(selector);
        return NodeList.prototype.isPrototypeOf(result)
          ? [...flatResults, ...result]
          : [...flatResults, result];
      }, [])
    : /^#/.test(cssSelectorString)
    ? document.querySelector(cssSelectorString)
    : document.querySelectorAll(cssSelectorString);
};